Utility vehicles are typically equipped with a pneumatic brake system and an electronic brake system. This means that a brake signal is sent electronically to a control unit by a driver. The control unit controls valves with which brake pressure in vehicle brakes is controlled. All kinds of sensors and additional functions are associated with the control unit. For example, stability control can be provided, namely control against tipping over because of excessively rapid cornering. The combination of a pneumatic brake system and an electronic brake system is also known for trailer vehicles.
In electronic brake systems, a low test brake pressure is controlled on the side of the vehicle on the inside of the turn for verifying the risk of tipping over. If the low test brake pressure is sufficient to lock wheels on the side of the vehicle on the inside of the turn, it is assumed therefrom that the load on the side of the vehicle on the inside of the turn is highly reduced and there is a risk of tipping over. The vehicle is then automatically fully braked to reduce the speed and thus to prevent tipping over. In this case, the test brake pressure is calculated as a function of a loading, so that the wheels on the inside of the turn lock at approx. 90% load reduction, starting from a relatively high coefficient of friction between the tires and the road. Detection of the axle loads by sensors and relatively accurate delivery of the test brake pressure are necessary for this purpose. Both are typically not provided for simple brake systems without an electronic brake system.
The forerunner of the electronic brake system was so-called antilock control without electronic transmission of the brake signal from the driver to the control unit. The control unit only had the task of monitoring signals of the wheel revolution rate sensors and reducing the effective brake pressure for locking wheels. Furthermore, trailer vehicles with antilock control and without an electronic brake system are widespread.